Hot-air power or pumping engine.



un. 668,626. Pmmd'reb. 2a, 19m.

- f c: a.' caen-WALL. HOT AIR POWER 0R PUMPING ENGlE'.

(Application tiled un'. I2, 189B.;

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UNITED STATES PATENT OFFICE.

CARL G. CRONWALL, OIF CHICAGO, ILLINOIS.

HOT-AIR'POWER OR PUMPING ENGINE.

SPECIFICATION forming part of Letters Patent N o. 668,626, datedFebruary 26, 1901.

Application filed March 12, 1898. Serial No. 673,678. (No model.)

To @ZZ whom it may concern:

Be it known that I, CARL G. CRONWALL, a subject of the King of Swedenand Norway, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in a Hot-AirPower or Pumping Engine, of which the following is a specification.

This invention relates to improvements in that class of air-engines inwhich a displacerpiston is reciprocated and the air alternately heatedand cooled; and it consists in certain peculiarities of theconstruction, novel arrangement, and operation of the various partsthereof, as will be hereinafter more fully set forth and specificallyclaimed.

The objects of my invention are to simplify yet so construct the enginethat greater power will be afforded than has heretofore been attained byengines of a similar type and also to enable parts of the engine to bemade of lighter or thinner material,and thereby facilitate the heatingand cooling of the air with in the air-cylinder.

Other objects and advantages will appear in the description hereinaftercontained.

In order to enable others skilled in the art to which my inventionpertains to make and use the same, I will new proceed to describe it,referring to the accompanying drawings, in which- Figure l isa centralvertical sectional view of my engine, showing the parts thereof in theposition they will occupy whenready for use. Fig. 2 is a similar viewtaken on line 2 2 of Fig. l looking in the direction indicated by thearrows and showing the water-jacket and displacer-piston with the rodsfor operating the latter. Fig. 3 is a perspective view of thecrank-shaftodetached; and Fig. 4 is a cross-sectional view, taken online 4 4; of Fig. 1, of the air-cylinder and displacer-piston, viewingthemv from the bottom.A

Similar letters refer to like parts throughout the different views -ofthe drawings.

A represents the supporting-frame, upon which the air-cylinder B ismounted and to which the fire-box C and fire-pot or heater C aresecured. Surrounding the air-cylinder B is a water-jacket B', which isprovided in its lower and upper portions with pipes b and b for thesupply and discharge of water.

The fire-pot or heater C' is preferably made of thin sheet-copper, andto reinforce or strengthen the same I vmay locate on itsinterior a steelor other metallic band c, which is preferably spiral in shape, as shown'in Fig. l of the drawings. The fire-box C surrounds the fire-pot orheater C and extends some distance therebelow to receive and retain theheat from the fire, which may be produced by means of `gas, oil, orother suitable fuel located beneath the firepot. On the upper part ofthe air-cylinder and water-jacket and on each side thereof is located anupright standard d, in which the crank-shaft E is journaled. This shaftis provided at about its middle with a crank c, to which is secured oneend of the pitrnan c', whose other end is secured to the lower portionof the powerpiston F, which is located and operates in the upper portionof the air-cylinder and is provided with suitable packing f to preventthe escape of air.

On one end of the crank-shaft E is mounted a balance-wheel E', and onthe other end of `said shaft is fixed at an angle to the crank e a crankc2, of greater length than the firstnamed crank and having pivotallysecured to its free endapitman-rod g, which is similarly connected atits lower end to an arm g, iXed Y to the lower end of avertically-movable rod g2, which passes through suitable stuffingboxesg3 in a lateral offset O in the casing of the water-jacket orair-cylinder. Secured at one of its ends to the rod g2 andextendinghorizontally through a vertical slot g5 in the airecylinder andout into said odset O is a rod g4, which is secured to the upper portionof the displac'er-piston G, 'located and operating in the air-cylinder.Said offset O has a faceplate O' bolted or otherwise secured to itsouter side and which can `be removed when it is desired to adjust thepoint of connection between the horizontal and vertical rods g4 and g3or to repair or replace any of the working parts. Hence it is notnecessary to disarrange the mechanism or remove anything but theface-plate for this purpose.

In the drawings I havel shown the upper end of the displacer-piston,which is closed, as being formed with a transverse depression h and withthe rod g4, secured in said depression, and I prefer to so form thepiston IOO and so secure the rod for the reason that such an arrangementwill allow the upper end of the displacer-piston and the lower end ofthe power-piston to come nearer together.

The displacer-piston, as shown in Figs. l and 4 of the drawings, issomewhat smaller than the interior of the air-cylinder and is providedon its exterior and near its upper portion with vertical ribs 7L', whichwill rest against the interior of the air-cylinder and keep thedisplacer-piston in proper position therein, besides affording spacebetween the exterior wall of the displacer-piston and the inner wall ofthe air-cylinder for the passage of air, as well as diminishing thefriction of the contacting surfaces. The displacer-pistou G is made ofthin material and is provided in its upper portion with a port oropening h2 for the passage of air.

In Fig. l of the drawings I have shown my engine with a construction forthe purpose of operating a pump which I may sometimes employ and whichconsists of a gear-wheel I, journaled on a suitable support and having acrank-pin or roller 1T, located within a yoke I, secured to a piston-rodL, which operates a piston within the pump-cylinder M and has near itsupper end a bearing Z, secured on a suitable arm or brace (not shown)for its snpport. The gear-wheel I meshes with a pinion N, secured to thecrank-shaft E, and when it is rotated it is evident that the gear-wheelI will be revolved, which operation will cause the piston-rod L to bereciprocated through the medium of the crank-pin or roller t' and theyoke I', with which it engages.

Instead of using the construction just above described for operating thepump it is evident that a belt may be applied to a wheel or pulleylocated on the crank-shaft and power transmitted therethrough foroperating various kinds of machinery.

The operation of my engine is asfollows: The air within the air-cylinderis expanded by the application of heat to the nre-pot and is contractedby the cooling effect of the water within the water-jacket, whichoperation causes the power-piston and displacer-piston to bereciprocated within the air-cylinder very much in the usual manner ofhotair engines, thus shifting the airand causing it to be alternatelyheated or cooled or eX- panded and contracted. The displacer-pistonbeing provided with an opening or port h2 in its upper portion, it isevident that as the said piston ascends by reason of the expansion ofthe air in the lower portion of the air-cylinder some of the cold airbetween the two pistons will be free to pass into the always-hotdisplacer-piston, there to become heated, thus causing said pistou toact as an air-reservoir and allowing it to be made 0f thinner materialthan would otherwise be required on account of the uniform or nearlyuniform pressure of air within and without the said piston. It isfurther apparent that as the crank e2 is on the crank-shaft E at anangle to the crank e and is longer than the last-named crank greaterpower will be attained by reason of the longer stroke and greater bodyof air employed and that when in about the position shown in Fig. l ofthe drawings the lower end of the power-piston F and the upper end ofthe displacer-piston G will be in close proximity to each other, thuscausing nearly all of the air to be forced to the lower portion of theair-cylinder to be heated and expanded.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is*

l. In an air-engine, the combination of an air-cylinder, with a hollowdisplacer-pistou located therein and having its top and bottom closedand an opening or port in its upper portion for the free passage of air,and a power-piston located in the upper portion of the air-cylinder,substantially as described.

2. In an air-engine, the combination with the air-cylinder, and areciprocating powerpiston therein; of a displacerpiston also therein,its end next the power-piston being fiat except for a transversedepression, a rod secured therein and projecting laterally through avertical slot in said cylinder, a reciprocating rod mounted in guidesand attached to said lateral rod, and means for moving the reciprocatingrod, as and for the purpose set forth.

3. In an air-engine, the combination with the air-cylinder having aVertical slot near its lower end, a lateral offset in the casingcovering said slot and having a removable faceplate, and a power-pistonreciprocating within the cylinder above said slot; of a displacer-pistonwithin the cylinder beneath the power-piston, a rod extending from thedisplacer-piston horizontally out through said slot, a vertical rodguided in stuffing-boxes in the top and bottom of the offset,connections between the horizontal and vertical rods, and meansfordriving the latter from a point entirely exterior to the cylinder andoffset, as and for the purpose set forth.

CARL G. CRONWALL. Witnesses:

CHAs. C. TILLMAN, E. A. DUGGAN.

IIO

